### Output Format:
You must output valid JSON. Do not add markdown or conversational text. Three fields:
- **answer**: Answer to the problem. Letter identifying which image best completes the sequence based on full problem analysis, comparisons between shapes, colors, orientations, and relations in rows and columns of the matrix.
- **confidence**: Confidence in your answer, ranging from 0.0 to 1.0. (1.0 meaning absolutely confident, 0.5 meaning not so sure, 0 meaning purely guessing, etc.)
- **rationale**: Short rationale for your answer.

### Example:
{
    "answer": "C",
    "confidence": 0.97,
    "rationale": "Sample explanation based on observations",
}
